bevels explained

Discussion in 'Straight Razors' started by neiasden, Sep 29, 2022.

  1. neiasden

    neiasden Member

    I'm guessing this is a tricky one. even though I kind of know what's being talked about I don't really understand it. the people on this forum are amazing at explaining things so hopefully somebody can explain devils so that they make sense. I read on them and try to follow but bevel angles? I'm missing something
     
  2. DaltonGang

    DaltonGang Ol' Itchy Whiskers

    A bevel is the sharp angled end of the Straight Razor. Hope this helps. :lam:

    .
     
  3. neiasden

    neiasden Member

    and they change the angle where this takes place at? I get that it's the sharp part but I don't get how you can change anything about it because it's flat and you grind it off how would you possibly hold it any different way to get a different degree angle was what I was trying to figure out and why they would need to measure it I'm not trying to figure out how to do it I'm just trying to figure out what it is they're doing why would a angle need changed and what are they planning on changing it to probably too far over my head
     
  4. Mr. Oldschool

    Mr. Oldschool Johnny Dangerously

    If you were to look at the edge of your razor under heavy magnification, the edge shape would be a lot more apparent. The shiny part of the leading edge is what we call the bevel. The angle corresponds with the thickness of the spine. When you set the blade on a hone, the only parts that actually touch the hone are the spine and the bevel. As you hone your razor repeatedly throughout its service life, both surfaces get ground away (the bevel and the spine) which gradually changes the angle to a flatter, more acute angle. This makes a change to the geometry of the blade, and adversely affects the performance (this usually takes place over many years, but one determined knucklehead can surely find a way to grind the thing down in a misspent weekend, I'm sure).
    There are various ways we try to correct this phenomenon. Many of us put 3M electric tape on the spine to prevent it from wearing, however, the angle will still change over time as the leading edge wears away, so instead of becoming flatter, it will become wider, or more oblique. Neither situation is desireable. Some people go to great lengths to measure the width from the spine to the leading edge, then calculate the best bevel angle, then adjust the width of the spine to get that angle (usually, again, by adding layers of tape. YMMV).
    The main thing to keep in mind is that a competently made razor had the bevel angle predetermined by the width of the spine. If you have a razor with little wear, it is probably safe to assume you can just trust the manufacturer's geometry. If you have a very worn razor, to the degree that the bevel angle is being seriously thrown off, it may just need to be retired. They do have a service life, which does have an end terminus.

    For the most part, when I see bevels mentioned around here, it isn't the angle that is being discussed, but rather "setting" the bevel. That is where you use a lower grit hone (1k) to grind out the dents, nicks, and imperfections in the literal edge where the bevel from one side meets the bevel from the other side. (You might be surprised how much damage our whiskers do to the edge of the blades) In order to get your edge true, you have to hone through until you have a clean, smooth edge. Then, after the bevel is set, and only then, you advance to the higher grit stones to refine the surfaces of the bevels. Basically, the sharpness is determined by the bevel being clean and correct the entire length of the edge. Everything after that is polishing the surfaces to a mirror finish, which gives the blade a smoother feel on your skin.

    Does that clear it up for you?

    Sent from my SM-G781U using Tapatalk
     
    PLANofMAN likes this.
  5. neiasden

    neiasden Member

    holy Cowyes. thank you for putting that so an idiot like me can remotely understand it. my problem is I'm so new I have no experience Hands-On but I've always been fairly smart to figure things out as long as I know what it is I'm trying to figure out and when I thought I had bevels understood kind of they started talking about degrees and stuff I knew nothing about so I asked for a response like you gave. you guys on here are amazing I don't know how you learn so much about this stuff just from doing it unless you do it thousands of times lol but thank you so much I don't know everybody's names but I have got some of the best answers on here unbelievable. I tell everybody I know this is the place to be

    UOTE="Mr. Oldschool, post: 2052263, member: 10203"]If you were to look at the edge of your razor under heavy magnification, the edge shape would be a lot more apparent. The shiny part of the leading edge is what we call the bevel. The angle corresponds with the thickness of the spine. When you set the blade on a hone, the only parts that actually touch the hone are the spine and the bevel. As you hone your razor repeatedly throughout its service life, both surfaces get ground away (the bevel and the spine) which gradually changes the angle to a flatter, more acute angle. This makes a change to the geometry of the blade, and adversely affects the performance (this usually takes place over many years, but one determined knucklehead can surely find a way to grind the thing down in a misspent weekend, I'm sure).
    There are various ways we try to correct this phenomenon. Many of us put 3M electric tape on the spine to prevent it from wearing, however, the angle will still change over time as the leading edge wears away, so instead of becoming flatter, it will become wider, or more oblique. Neither situation is desireable. Some people go to great lengths to measure the width from the spine to the leading edge, then calculate the best bevel angle, then adjust the width of the spine to get that angle (usually, again, by adding layers of tape. YMMV).
    The main thing to keep in mind is that a competently made razor had the bevel angle predetermined by the width of the spine. If you have a razor with little wear, it is probably safe to assume you can just trust the manufacturer's geometry. If you have a very worn razor, to the degree that the bevel angle is being seriously thrown off, it may just need to be retired. They do have a service life, which does have an end terminus.

    For the most part, when I see bevels mentioned around here, it isn't the angle that is being discussed, but rather "setting" the bevel. That is where you use a lower grit hone (1k) to grind out the dents, nicks, and imperfections in the literal edge where the bevel from one side meets the bevel from the other side. (You might be surprised how much damage our whiskers do to the edge of the blades) In order to get your edge true, you have to hone through until you have a clean, smooth edge. Then, after the bevel is set, and only then, you advance to the higher grit stones to refine the surfaces of the bevels. Basically, the sharpness is determined by the bevel being clean and correct the entire length of the edge. Everything after that is polishing the surfaces to a mirror finish, which gives the blade a smoother feel on your skin.

    Does that clear it up for you?

    Sent from my SM-G781U using Tapatalk[/QUOTE]
     
  6. gssixgun

    gssixgun At this point in time...

    Supporting Vendor
    Bevel angle was determined hundreds of years ago, it has been generally accepted to be 16-17° Included

    The theory is that as you hone the Spine and Edge will wear away Evenly and Equally and you will keep that angle throughout the SR's life
    In reality the spine is actually softer than the edge (Tested) the older the razor the more this is true, this with the fact that few SR's are perfectly straight (Warps) means that we find many razors with blown geometry from honing..

    We often use Electrical tape to compensate for these issues, (1 lawyer of standard 3M 700 changes the angle .67° of one degree on a 6/8 razor) simple rule of thumb "Until you can hone without wearing the tape on the spine keep using tape on the spine"

    Although it is true mathematically that using tape will change the angle, personally after honing over 30,000+ razors I have NEVER had to correct one for a high angle, but have corrected thousands for blown spines..

    Truth: 90% of honing is done in the bevel set, after that, it is just refining the scratches for comfort :)

    Hope that helps
     
  7. neiasden

    neiasden Member

    Lord yes that helps a lot it also is going to cost me to Google to figure some stuff out lol do you have any videos of you restoring any or doing anything I've seen just about every YouTube video and I don't know if I've seen you in any but you would be excellent at making one. you are very articulate and knowledgeable which amazes me how you guys learn this stuff with no books or anything on it I don't even know how you would measure a degree that's tape would change lol and I don't need to know because what you said make sense but I'm one of those people that just soak up everything I can whether I need it or not. but thank you for making this so much easier. I have a hard enough time with MS kicking my butt I can't always do the things the way you all safe to do them or I've read or seen so I have to make up some kind of something to help me do whatever it is I'm trying to do I have more little gadgets I've made it's hilarious I wish I could just do things normal
     
  8. gssixgun

    gssixgun At this point in time...

    Supporting Vendor
  9. neiasden

    neiasden Member

    okay these work I'm watching the one about taking a frown out I didn't know you could do that LOL learn something everyday when you starting at nothing
     
  10. PLANofMAN

    PLANofMAN Eccentric Razor Collector Staff Member

    Moderator Article Team
    This is a DE blade edge under an electron microscope. Most DE blades have a double bevel, the bevel and what we call a micro bevel or edge bevel. Feather DE blades have a triple bevel, also sometimes referred to as a tri-faceted edge.

    The double bevel is seen often in razor blades (including straight razors and kamisoris), Japanese kitchen knives, chisels and plane irons, even axes and hatchets. It gets talked about the most on straight razor forums and knife forums though.
    _storage_emulated_0_Pictures_comica_cartoon1664647785419 (2).jpg
     
    DrStrange, Steve56 and gssixgun like this.
  11. neiasden

    neiasden Member

    dang, this hobby goes as deep as you want to go with it LOL thank you for your input
     
    PLANofMAN likes this.

Share This Page